Roll PDFium from 8516651130b5 to 9a3f345ba7c4 (10 revisions)

https://pdfium.googlesource.com/pdfium.git/+log/8516651130b5..9a3f345ba7c4

2020-07-18 tsepez@chromium.org Make ownership of CXFA_ThisProxy explicit (and sane).
2020-07-18 dhoss@chromium.org Mass assert OpenDocument*() in tests
2020-07-18 thestig@chromium.org Add experimental FPDFImageObj_GetRenderedBitmap() API.
2020-07-17 dhoss@chromium.org Add test for dropped clipping paths when saving dirty text
2020-07-17 tsepez@chromium.org Remove include of cxfa_document.h from cxfa_layoutitem.h.
2020-07-17 tsepez@chromium.org Track CXFA_Lists in xfa/fxfa/ layer.
2020-07-17 vmiklos@collabora.co.uk Add FPDFSignatureObj_GetContents() API
2020-07-15 tsepez@chromium.org Explicitly track CXFA_List and its subclasses outside constructor.
2020-07-15 bungeman@google.com Add nogncheck to conditional includes.
2020-07-15 dmazzoni@chromium.org Add FPDF_StructElement_GetStringAttribute

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/pdfium-autoroll
Please CC pdfium-deps-rolls@chromium.org on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Bug: None
Tbr: pdfium-deps-rolls@chromium.org
Change-Id: I6eb1d6235131651f7af02a4db38faf1275f755c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2305793Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#789751}

DEPS

@@ -215,7 +215,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.
-  'pdfium_revision': '8516651130b5e2b1a382ad9d9e43e4eccc3abc81',
+  'pdfium_revision': '9a3f345ba7c49cdc78e8caf4e667d94da8fcbbd9',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.